perustuu

Perustuu is a Finnish verb form meaning is based on or to be based on. It is the third-person singular present indicative form of the verb perustua. The word is commonly used to indicate that a claim, finding, argument, or document rests on a particular source, evidence, or principle. In Finnish, the construction often follows with a noun phrase in the illative case to denote the basis, as in tutkimukseen perustuu “is based on research,” or aineistoon perustuu “is based on data.”

Usage and context can vary from academic and journalistic writing to everyday speech. Perustua is used to attribute legitimacy or foundation to statements, theories, or conclusions. The expression is compatible with both explicit sources and more general bases, such as traditions, laws, or observed phenomena. It can appear in active constructions (esimerkiksi tämä päätelmä perustuu uusiin todisteisiin) as well as in impersonal or passive-like forms common in Finnish prose.

Etymology and related forms: perustuu derives from the noun perusta, meaning foundation or basis. Related words include perustua (to base), perusta (foundation), and peruste (reason, basis). The term is characteristic of Finnish ways of tying assertions to underlying grounds, evidential backing, or normative rules.

See also: perusta, peruste, perustaa.